1. Field of the Invention
The present invention relates to a backlight assembly of a liquid crystal display (LCD) device, and more particularly, to a backlight assembly of a liquid crystal display (LCD) device, in which protrusions are formed at a contact surface between a side supporter and a cover shield, to prevent deformation of the cover shield from an external force, and to prevent disconnection of a wire positioned between the side supporter and the cover shield.
2. Discussion of the Related Art
Recently, efforts have been undertaken to research and develop various flat display devices such as liquid crystal displays (LCD), plasma display panels (PDP), electroluminescent displays (ELD), and vacuum fluorescent displays (VFD). Some species of flat display devices have already been applied to displays for various applications.
Among the various flat display devices, liquid crystal display (LCD) devices have been most widely used because of their thin profile, low weight, and low power consumption. The LCD devices provide a substitute for a Cathode Ray Tube (CRT). In addition to mobile type LCD devices, such as displays for notebook computers, LCD devices have been developed for computer monitors and televisions to receive and display broadcasting signals.
Despite various technical developments in LCD technology having applications in different fields, research in enhancing the picture quality of the LCD device has been, in some respects, lacking as compared to other features and advantages of the LCD device. In order to use LCD devices in various fields as a general display, LCD devices should have a high quality picture, such as high resolution and high luminance with a large-sized screen, while still maintaining low weight, a thin profile, and low power consumption.
In general, the LCD device includes an LCD panel for displaying images and a driving part for applying a driving signal to the LCD panel. The LCD panel includes first and second substrates bonded to each other with a predetermined interval therebetween and a liquid crystal layer in the interval between the first and second substrates.
Moreover, the LCD device typically requires an additional light source. For example, a backlight assembly for emitting and guiding light is typically used in a transmitting type LCD device.
The backlight assembly may be classified into an edge type and a direct type.
In an edge type backlight assembly, silhouettes of light-emission lamps appear on the LCD panel. Thus, there must be a predetermined interval between the light-emission lamps and the LCD panel. Also, a light-scattering means is provided in the edge type backlight assembly for uniformly scattering light. Accordingly, all the components increase the thickness of a profile in the LCD device of the direct type backlight assembly.
Also, as the size of the LCD panel increases, the size of a light-emission area in the backlight assembly increases. Where a large-sized direct type backlight assembly is used, it is difficult to obtain a flat light-emission area if the light-scattering means does not have a sufficient thickness. Thus, it is necessary to provide a light-scattering means having a sufficient thickness.
In the edge type backlight assembly, light-emission lamps are formed at one side of a light-guiding plate, and light is dispersed on an entire surface of the LCD panel by the light-guiding plate. Problems related to edge type backlight assembly include low luminance since the light-emission lamps are provided at one side of the light-guiding plate and the light is transmitted through the light-guiding plate. Also, complicated techniques for designing and fabricating the light-guiding plate are required in order to obtain a uniform luminous intensity in the LCD device having the edge type backlight assembly.
Accordingly, a direct type backlight assembly is generally applied to an LCD device that requires high luminance. Furthermore, the edge type backlight assembly is generally used for a notebook PC or a monitor PC which requires a thin profile.
Hereinafter, a direct type backlight assembly according to the related art will be described with reference to the accompanying drawings.
FIG. 1 is a perspective view of a direct type backlight assembly according to the related art. FIG. 2 is a cross sectional view along line I-I′ of FIG. 1.
As shown in FIG. 1 and FIG. 2, a direct type backlight assembly according to the related art includes a plurality of lamps 111, a side supporter 108, a protection cap 105, a PCB 104, a cover shield 103, a first supporter 106a, a second supporter 106b, and a wire 107.
At this time, the plurality of lamps 111 are arranged at fixed intervals along one direction inside an outer case 102. Then, the side supporter 108 is provided at one side of the outer case 102, wherein the side supporter 108 has a plurality of U-shaped curved portions, each for supporting one end of a lamp of the plurality of lamps 111. Also, the protection cap 105 is provided between each inner wall of a U-shaped curved portion in the side supporter 108 and each end of the lamp. The PCB 104, in which an inverter (not shown) is mounted, is formed at a rear corner of the outer case 102. The cover shield 103 protects each end of the lamps 111 and the first PCB 104, wherein the cover shield 103 has one bent edge 103a for covering each end of the lamps 111, and a second bent edge 103b for covering one rear edge of the outer case 102.
In addition, the first supporter 106a protrudes from the protection cap 105 toward the one bent edge 103a of the cover shield 103, wherein the first supporter 106a has a via-hole. The second supporter 106b protrudes from the protection cap 105 perpendicular to the first supporter 106a, and extends toward the second bent edge 103b of the cover shield 103 through the outer case 102. Also, the second supporter 106b has a via-hole. The wire 107 electrically connects the electrode 120 formed at one end in each of the lamps 111 with the inverter of the PCB 104 by the via-holes of the first and second supporters 106a and 106b. 
Furthermore, first and second protrusions 177a and 177b are formed on opposite surfaces of the outer case 102 and the other edge 103b of the cover shield 103, respectively. The first protrusion 177a is connected with the second protrusion 177b by a screw 190, whereby the cover shield 103 and the outer case 102 are fixed to each other.
In addition, although not shown, the direct type backlight assembly according to the related art includes another side supporter, another protection cap, another PCB, another cover shield 146, another first supporter, another second supporter, and another wire.
The side supporter is provided at the other side of the outer case 102, wherein the side supporter has a plurality of U-shaped curved portions, each for supporting a second end of each of the lamps 111. The protection cap is provided between each inner wall of the U-shaped curved portions in the side supporter and the other end in each of the lamps 111 to protect an electrode in the second end of the lamp. Then, the PCB, in which an inverter (not shown) is mounted, is formed at the other rear corner of the outer case 102. The cover shield 146 protects the other end in each of the lamps 111 and the PCB, wherein the cover shield 146 has a first edge 146a for covering the second end of each of the lamps 111, and a second edge 146b for covering a second rear edge of the outer case 102.
The first supporter protrudes from the protection cap towards the first edge 146a of the cover shield 146, wherein the first supporter has a via-hole. The second supporter protrudes from the protection cap perpendicular to the first supporter and extends toward the other edge 146b of the cover shield 146 through the outer case 102. In this case, the second supporter also has a via-hole. The wire electrically connects the electrode formed at the other end in each of the lamps 111 with the inverter of the PCB by the via-holes of the first and second supporters.
In addition, first and second protrusions 199 are formed on opposite surfaces of the outer case 102 and the second edge 146b of the cover shield 146. The first protrusion is connected with the second protrusion by a screw, whereby the cover shield 146 and the outer case 102 are fixed to each other.
The protection cap 105 protects the electrodes 120 formed at both ends in each of the lamps 111. For this, the protection cap 105 is formed of rubber. The first and second supporters 106a and 106b are formed as one body with the protection cap, whereby the first and second supporters are formed of rubber.
Furthermore, a reflective sheet (not shown) is provided on an upper surface of the outer case 102, so as to reflect the light emitted from the lamps 111 toward a display part of an LCD panel 100.
Referring to FIG. 2, optical sheets 110 of a light-diffusion sheet 110a and a polarizing film 110b are provided on an upper surface of the side supporter 108. The light-diffusion sheet 110a receives the light emitted from the lamps 111 and uniformly diffuses the light. The polarizing film 110b receives the light diffused by the light-diffusion sheet 110a and provides the light to the display part of the LCD panel 100 after improving luminance.
A side panel 109 is provided between the optical sheets 110 and the LCD panel 100. The side panel 109 covers the upper edges of the optical sheets 110 and the lower edge of the LCD panel 100.
In the direct type backlight assembly according to the related art, a top case 101 is provided to cover the upper edge of the LCD panel 100 and the lateral side of the side panel 109. The top case 101 fixes the LCD panel 100 and the side panel 109.
However, the direct type backlight assembly according to the related art has several disadvantages, as illustrated in FIG. 3.
FIG. 3 is a cross sectional view showing deformation of a cover shield. In addition, FIG.3 show the disconnection of a wire in a backlight assembly according to the related art when applying an external force.
In the direct type backlight assembly according to the related art, since the cover shield 103 is formed of metal, one edge 103a of the cover shield 103 may be bent toward the lamp 111 when the external force is applied to one edge 103a of the cover shield 103.
When the cover shield 103 deforms, one edge 103a of the cover shield 103 presses the first supporter 106a. Thus, the first supporter 106a flexes against one end of the lamp 111. In this state, the wire 107 passing through the via-hole of the first supporter 106a is also inserted toward one end of the lamp 111, whereby the corner of the outer case 102 is exposed. When the wire 107 is in contact with the corner of the outer case 102, the wire 107 is damaged by the external force. If a large external force is applied, the wire 107 may be disconnected. Furthermore, the wire, which is connected with the electrode formed at the other end of the lamp 111, may be damaged due to the deformation of the cover shield 146.